name lookup timed out - Please help

I have a VPS server running WHM 11.30.5 (build 3) CENTOS 5.7 i686 virtuoso. I have several Wordpress blogs/sites running on this server. These sites have been running flawlessly for over a year. Regular updates to the wordpress software has been done.

About 2 weeks ago the blog stopped auto posting scheduled posts, it stopped being able to connect to twitter to tweet new blog posts.

I have since updated Apache and mysql to the latest version as well as php. However none of these have solved the issue. I have tried to get them to work with and without the firewall enabled. Since these changes the sites are very slow to respond, however load on the server is a minimal .01-.04

I thought the issue was with cURL, however that does not seem to be the case. I have tried the WP forums, but nothing. I believe this is a server issue. Anyone have ANY idea what could be the issue or things to try to resolve it?